JP5963160B2 - Spherical motor - Google Patents

Description

  The present invention relates to a sensor for a spherical motor capable of rotating with multiple degrees of freedom.

  A multi-degree-of-freedom actuator having 3 degrees of freedom or more has been proposed. For example, as in Patent Document 1, a spherical inner member is rotatably held inside a spherical outer member having a hollow shell structure, and one member is a stator and the other member is a rotor. A spherical motor that rotates a rotor with three or more degrees of freedom is known. In this spherical motor, as a means for detecting the rotation of the rotor, for example, as disclosed in Patent Document 2, an encoder is installed on the holding shaft of the gimbal mechanism, and rotation around each axis is detected. Further, there is a means for obtaining rotation information of the rotor by arranging a Hall element / IC on the stator side and detecting a magnetic field of a magnet mounted on the rotor.

  Non-Patent Document 1 describes a method of measuring the angular velocity / rotation angle of a sphere using a plurality of laser mouse sensors. In this document, “Several methods of measuring the movement of a sphere with a mouse sensor have been proposed, but our method has a high degree of freedom in sensor placement, is simple in computation, and uses multiple sensors. In addition, it is possible to measure plane motion by transforming the formula, but because it is a velocity measurement method, numerical integration is required to obtain the angle and position, and slight measurement is required. There is a weak point that the error will become a big error later.There is also a method of directly measuring the angle with a sphere with a large number of sensors and complicated patterns, but it is more useful if it can be realized with a small number of sensors. "We studied a method that enables absolute measurement by using a particle filter together with the method."

JP 2009-77463 A JP 2009-100656 A JP 2009-296864 A

The Japan Society of Mechanical Engineers Robotics and Mechatronics Lecture May 26-28,2011

  By the way, when installing an encoder like patent document 2, it is necessary to install the holding axis | shaft of a gimbal mechanism, and since rotation of a rotor is a rotation axis reference | standard, the restriction | limiting of a rotation range will arise. Further, when the Hall element is installed on the stator of the spherical motor to acquire the rotation information of the rotor as in Patent Document 3, the magnetic field (magnetism) detected by the Hall element / IC even when the rotor is rotated around one axis. Since the waveform in which the change is detected is not necessarily sinusoidal, it is difficult to calculate an accurate amount of movement for interpolating between the magnetic poles of the rotor using information from the Hall element. For this reason, when only the zero cross point on the waveform where the N pole and S pole are switched by the Hall element / IC without performing interpolation processing is used as the detection point and used as rotation information, the rotor of the spherical motor of this embodiment has one axis When the rotor is rotated around, the number of pole pairs of the magnet N pole and S pole is 2 (2 combinations) during a mechanical angle of 360 °, and the detection resolution is 90 °. Hall elements / ICs may be added to increase the detection resolution per rotor revolution, but in this case, other main members (stator magnetic poles, bearings, etc.) due to increased costs due to increased number of elements and increased volume / quantity of sensors There is a risk that the placement restrictions on Also, the number of wirings to each element (for example, 4 elements per element, 4 × n when the number of elements is n, 4 × n) is drastically increased and may be complicated. . Also, the method using the Hall element is a trigger that the magnet crosses in front of each sensor, and only the crossing in front of the magnet becomes output information, so the single sensor cannot detect the rotation direction of the rotor, For this reason, it is indispensable to collect information obtained from a plurality of sensors and perform arithmetic processing. In addition, because detection is performed by switching poles (N pole to S pole, S pole to N pole), sensor output cannot be obtained unless it passes near the pole switching (for example, even if the rotor rotates 90 degrees, If the magnetic pole is not switched, no detection signal is output during that period. Further, the configuration of the magnetic field inside the spherical motor is extremely complicated, and in order to increase the detection accuracy of the position / velocity / angle of the rotor, the number of elements of the sensor must be increased, but this is difficult for the above reason.

  The present invention does not require the sensor to be fixed to a holding shaft such as a gimbal mechanism, and therefore does not limit the rotation of the rotor and is not affected by magnetism, and thus the rotational direction / rotational speed of the rotor with high resolution. An object of the present invention is to obtain a spherical motor equipped with a sensor capable of calculating a rotation amount and the like.

The invention described in claim 1 includes a mechanism for detecting an operation of a rotor of a spherical motor that can rotate in an arbitrary direction by an optical position sensor having an output number of 3 or more, and the mechanism is in a state of rotation of the rotor. And the optical position sensor detects speed components in three directions on the rotor surface, and the rotor rotation state calculator calculates the speed components in the three directions on the rotor surface. The spherical motor is characterized in that the three-dimensional angular velocity vector ω = (ω ₁ , ω ₂ , ω ₃ ) is calculated based on According to the invention described in 請 Motomeko 1, it can increase the accuracy of detecting the direction of rotation / rotation speed / rotation amount of the (b) over data.

According to a second aspect of the present invention, in the first aspect of the invention, the optical position sensor is disposed at at least two positions of an angle forming a known included angle, and is disposed at the two positions. the position of the optical position sensor is shown a center of rotation by a vector r ₁ and r ₂ as the origin, the vector r ₁ and r velocity component and the vector r ₁ in a specific direction at the position of ₂ and r ₂ The three-dimensional angular velocity vector ω = (ω ₁ , ω ₂ , ω ₃ ) is calculated based on the above component .

According to a third aspect of the invention, in the first or second aspect of the invention, the rotation amount of the rotor is calculated by integrating the three-dimensional angular velocity vector ω = (ω ₁ , ω ₂ , ω ₃ ). The rotation speed of the rotor surface is calculated by multiplying the three-dimensional angular velocity vector ω = (ω ₁ , ω ₂ , ω ₃ ) by the radius of the rotor .

According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the rotor has a spherical surface covered with an outer shell member, and the outer shell member of the rotor is exposed to a light emitting element. It is characterized in that coating or printing is performed in which light transmission or absorption is prevented, light that is necessary and sufficient for the light receiving element to detect the amount of movement is reflected, and the amount of reflected light changes due to movement. According to the fourth aspect of the invention, high-quality information with respect to the rotation of the rotor can be obtained, and high-precision detection accuracy can be realized.

  According to a fifth aspect of the invention, there is provided an arithmetic mechanism according to any one of the first to fourth aspects, wherein the signal detected from the optical position sensor is arithmetically processed to calculate a rotational state of the rotor. It is characterized by that.

  A sixth aspect of the invention is characterized in that, in the invention according to any one of the first to fifth aspects, a distance from the optical position sensor to the rotor is 1.0 to 3.0 mm.

  According to a seventh aspect of the present invention, in the invention according to any one of the first to sixth aspects, the rotor has a diameter of 40 mm or less.

  The invention according to claim 8 is the invention according to any one of claims 1 to 7, further comprising distance adjusting means capable of adjusting a distance between the optical position sensor and the outer peripheral surface of the rotor. It is characterized by that. The optimal distance between the optical position sensor and the rotor varies depending on the performance of the optical position sensor and the rotational speed of the rotor. Therefore, by making it possible to adjust the distance between the optical position sensor and the rotor, the rotation detection function suitable for the spherical motor can be set.

  The invention according to claim 9 is the invention according to any one of claims 1 to 8, wherein the substrate to which the optical position sensor is attached, a shaft for holding the substrate, and the shaft as the axis. A shaft holding member that holds the shaft in a state where movement in a direction is possible, and the shaft holding member is fixed to a stator of the spherical motor, and the outer peripheral surface of the optical position sensor and the rotor is moved by moving the shaft. The distance between the two is adjusted.

  According to the present invention, since it is not necessary to use a holding shaft such as a gimbal mechanism in order to obtain a sensor output, a plurality of output shafts (multiple degrees of freedom) are realized without limiting the rotation (movable range) of the rotor. In addition, it is possible to calculate the rotation direction / rotation speed / rotation amount of the rotor with high resolution regardless of the number of poles of the rotor without being influenced by magnetism. Further, by using an optical position sensor having three or more outputs, it is possible to calculate the rotational direction / rotational speed / rotation amount of the rotor with high resolution.

It is a disassembled perspective view of the spherical motor of an embodiment. FIG. 2 is an exploded perspective view in which a part of FIG. 1 is a perspective view. It is a perspective view which shows the structure of an optical position sensor. It is a perspective view of a stator. It is a side view which shows the positional relationship of a rotor surface and an optical sensor. It is a block diagram of a control system in an embodiment. It is a principle figure used for description of the principle of a calculation.

  An example using the present invention will be described with reference to the drawings. 1 and 2 show a spherical motor 100. The spherical motor 100 includes a stator 110. The stator 110 has a substantially spherical shell structure and is composed of hemispherical portions 111 and 112. A plurality of stator magnetic poles 113 are supported on the inner peripheral surface of the stator 110.

  The magnetic pole 113 has salient poles that are only partially visible in the figure. The salient pole has an extending portion that is not visible in the drawing extending in the direction of the center of rotation, and a resin bobbin 114 around which the field coil 115 is wound is attached to the extending portion. The tip of the salient pole (tip of the magnetic pole 113) has a salient pole surface 116 that faces the outer peripheral surface of the inner rotor 120 described later.

  A rotor 120 is housed inside the stator 110 having a spherical shell structure. The rotor 120 has a spherical structure. The rotor 120 is covered with a cover part 121 on the outside. The cover part 121 is made of a nonmagnetic material having a diameter of 40 mm or less, and has a substantially spherical shell structure having a smooth outer peripheral surface. Inside the cover 121, an inner sphere 124 having a plurality of rotor magnets 125 on the outer peripheral surface is housed. That is, the rotor magnet 125 is not exposed on the outer peripheral surface of the rotor 120 and is disposed inside the cover portion 121. The rotor magnet 125 is a permanent magnet magnetized in a disk shape and constitutes a magnetic pole on the rotor 120 side.

  The rotor 120 is held inside the stator 110 by a spherical bearing structure (not shown) arranged on the stator so that the rotor 110 can rotate with respect to the stator 110 with three or more degrees of freedom. A spherical bearing structure (not shown) has a structure in which a bearing ball is rotatably held at the tip of each of a plurality of protrusions protruding from the inner peripheral surface of the stator 110 toward the rotation center. A plurality of the protrusions are arranged so as to surround the rotor 120 from the periphery. The bearing ball supports the outer peripheral surface of the cover portion 121, so that the rotor 120 is held inside the stator 110 in a state where the rotor 120 can rotate with three or more degrees of freedom.

  An optical position sensor 117 is disposed inside the stator 110. The optical position sensor 117 includes a light emitting element and a light receiving element, and detects light emitted from the light emitting element and reflected from the surface of the rotor 120 by the light receiving element. The optical position sensor 117 receives the surface illuminated by the light emitting element as continuous image data, and compares the image data with the image data of a unit time ago (difference in which direction and how much is moving). Is obtained in the directions of two orthogonal axes.

  FIG. 3 shows an optical position sensor assembly 200. The optical position sensor assembly 200 includes a substrate 201, an optical position sensor 117, a shaft 203, and a holding unit 204. The substrate 201 is an electronic substrate on which an optical position sensor 117 that is made into an IC is attached. The substrate 201 has a predetermined print pattern, and the terminals of the optical position sensor 117 are soldered thereto, whereby the optical position sensor 117 is fixed to the substrate 201. A shaft 203 is fixed to the back side of the portion of the substrate 201 where the optical position sensor 117 is attached. The shaft 203 is a cylindrical member, and one end face thereof is fixed to the substrate 201. The shaft 203 is held by the holding unit 204 in a state where it can move in the axial direction.

  The holding part 204 includes a cylindrical part 204a and a disk-like flange part 204b. A hole reaching the shaft 203 is provided in the cylindrical portion 204a, and a set screw 205 is attached to the hole. A female screw structure is formed inside the hole to which the set screw 205 is attached, and a male screw structure is formed outside the set screw 205. As the female screw structure and the male screw structure are engaged with each other, the set screw 305 is screwed into the hole provided in the cylindrical portion 204a. By turning the set screw 205 and tightening the shaft 203, the shaft 303 can be fixed to the holding portion 204. Further, by loosening the set screw 205, the shaft 203 can be moved in the axial direction with respect to the holding portion 204.

  FIG. 4 is a perspective view of the stator 110. As shown in FIG. 4, the stator 110 is provided with a hole 210 penetrating inward. The optical position sensor 117 side of the optical position sensor assembly 200 is inserted into the hole 210, and the optical position sensor 117 is stored inside the hole 210. In this state, the flange portion 204 b contacts the edge portion of the hole 210, and the optical position sensor assembly 200 is attached to the stator 110. Further, in a state where the optical position sensor assembly 200 is attached to the stator 110, the sensor surface of the optical position sensor 117 faces the outer peripheral surface of the rotor 120 (see FIGS. 1 and 2).

  In the example shown in FIG. 4, two optical position sensor assemblies 200 are arranged at an angle forming a known narrow angle (90 ° in this example). From the outputs of the two optical position sensors 117, the rotation direction / rotation speed / rotation amount of the rotor 120 and the like are calculated. Details of the calculation in this calculation process will be described later.

  In a state where the optical position sensor assembly 200 is attached to the stator 110, the set screw 205 is loosened, the shaft 203 is moved in the axial direction with respect to the holding portion 204, and the optical position sensor 117 is held inside the stator 110. The distance between the rotor 120 (see FIGS. 1 and 2) can be adjusted.

  4 shows a magnetic pole assembly 220 that includes the salient pole surface 116, the bobbin 114, and the field coil 115 shown in FIG. The magnetic pole assembly 220 is attached to the hole 211 provided in the stator 110 with the same structure as the optical position sensor assembly 200.

  As a method for adjusting the distance between the optical position sensor 117 and the rotor 120 (see FIGS. 1 and 2) held inside the stator 110, a structure using shims or washers may be employed. Hereinafter, this example will be described. FIG. 5 is a side view showing the positional relationship between the rotor surface and the optical position sensor. An optical position sensor 117 is disposed on the inner peripheral surface of the stator 110. In the positional relationship between the optical position sensor 117 and the rotor 120 described later, a distance d from the surface of the rotor 120 to the optical position sensor 117 is ensured to be 1.0 to 3.0 mm. Here, the optical position sensor 117 is fixed to the substrate 131, and the substrate 131 is fixed to the hemispherical portion 112 constituting the stator outer shell by screws 132 and 133. In this structure, a washer, shim, or the like is sandwiched between the substrate 131 to which the optical position sensor 117 is fixed and the hemispherical portion 112 constituting the stator outer shell, that is, a portion denoted by reference numeral 134, thereby removing the optical position sensor 117. The distance d to the rotor 120 can be finely adjusted.

  FIG. 6 shows a block diagram of the control system calculation in the embodiment. The drive system shown in FIG. 6 includes a field coil energization pattern generation unit 301. The field coil energization pattern generation unit 301 generates an energization pattern of a drive current supplied to the plurality of field coils 115 of the spherical motor 100.

  The field coil energization pattern generation unit 301 receives a rotation command instruction signal that instructs which direction and how much the rotor 120 of the spherical motor 100 is rotated. Based on the rotation command instruction signal, the field coil energization pattern generation unit 301 generates an energization pattern of a drive current that flows through the plurality of field coils 115.

  A signal for determining the energization pattern of the field coil 115 is sent from the field coil energization pattern generation unit 301 to the drive output unit 302. The drive output unit 302 includes a switching element and supplies a drive current based on the energization pattern to the field coil 115. The magnetic attraction force and magnetic repulsion generated between the magnetic pole 113 on the stator 110 side and the rotor magnet 125 on the rotor 120 side are switched by switching the drive current supplied from the drive output unit 302 to the plurality of field coils 115. The force is appropriately switched, and the rotor 120 rotates. That is, the drive system shown in FIG. 4 performs drive control of the spherical motor 100 based on the rotation command instruction signal so that the rotor 120 performs rotation instructed by the rotation command instruction signal.

  As shown in FIG. 6, the optical position sensor 117 includes a light emitting element 118 and a light receiving element 119. As the light emitting element 118, for example, a light emitting diode or a laser light source is used, and as the light receiving element 119, for example, various optical sensors are used. Irradiation light from the light emitting element 118 is reflected by the surface of the rotor 120, and the reflected light is detected by the light receiving element 119. The wavelength of light to be used is not particularly limited, but visible light or infrared light is used. The signal output from the light receiving element 119 and detected from the reflected light of the rotor 120 (output of the optical position sensor 117) includes information relating to the rotation state of the rotor 120, and the detection signal of the light receiving element 119 is the rotor rotation. Input to the state calculation unit 303.

  The rotor rotation state calculation unit 303 calculates the rotation state of the rotor 120 such as the rotation direction, the rotation amount, and the rotation speed based on the detection signal output from the light receiving element 119. That is, when the rotor 120 rotates, the surface of the rotor 120 (the surface of the cover part 121) moves relative to the optical position sensor 117. At this time, the moving direction and moving amount of the surface of the rotor 120 are detected by the light receiving element 119, and the moving direction and moving amount of the surface of the rotor 120 are calculated from the output of the optical position sensor 117. Further, the attitude of the rotor 120 can be obtained by detecting the rotational speed of the rotor 120 by an optical position sensor and integrating it. Since the position of the optical position sensor 117, the position of the rotation center of the rotor 120, and the dimensions of the stator, the bearing, and the rotor are predetermined values in advance, the direction of movement and the amount of movement of the surface of the rotor 120 described above It is calculated whether the rotor 120 is rotated with only an angular displacement. Here, by calculating the change in the rotation amount per measurement time, the rotation speed of the rotor 120 and the speed change per measurement time are obtained as acceleration. With the above method, the rotor rotation state calculation unit 303 obtains the rotation state of the rotor 120.

  Information on the rotation state of the rotor 120 calculated by the rotor rotation state calculation unit 303 is sent to the field coil energization pattern generation unit 301. Thus, the field coil energization pattern generation unit 301 acquires information about the rotation state (rotation method, direction, and rotational movement amount) of the rotor 120 based on the detection signal from the light receiving element 119.

  The field coil energization pattern generation unit 301 compares the path for reaching the target position based on the rotation command instruction signal with the actual rotation state of the rotor 120 obtained from the optical position sensor 117, and the difference is The calculation for adjusting the energization pattern to the field coil 115 is performed so as to be eliminated, and the result is reflected in the output to the drive output unit 302. By performing this feedback control, the rotational accuracy of the rotor can be improved.

(Specific example of calculation)
Hereinafter, an example of the calculation performed in the rotor rotation state calculation unit 303 will be described. FIGS. 7A to 7E show principle diagrams used for explaining the principle of calculation. FIG. 7A shows an example in which optical position sensors are arranged at two positions indicated by vectors r ₁ and r ₂ . First, for the sake of simplicity, the rotor radius is set to 1, and a plane on which two optical position sensors whose positions are indicated by r ₁ and r ₂ is present is taken as the xy plane of the stator coordinate system (see FIG. 7A). Here, the angle from the x-axis is θ _i , and the vector r _i is expressed by Equation 1.

Further, the angular velocity ω (ω ₁ , ω ₂ , ω ₃ ) of the rotor in the stator coordinate system is expressed by Equation ₂ .

Using Equations 1 and 2, the surface velocity at each r _i point is expressed by Equation 3.

Since r _i is in the xy plane, if the horizontal component (in the xy plane) of the output of the optical position sensor is Δh _i and the vertical component (z-axis direction) is Δv _i , it is shown in FIG. Due to the relationship, Equation 4 is obtained.

Here, when the detection direction of the optical position sensor does not coincide with the xy plane, h and v components are calculated from the output of the optical position sensor by coordinate rotation conversion. Here, Equation 4 can be solved if r ₁ and r ₂ are linearly independent, and the general solution is Equation 5.

A specific example will be described below. For example, as shown in FIG. 7C, when θ1 = 0 and θ2 = (π / 2), ω ₁ , ω ₂ , and ω ₃ are expressed by Equation 6.

For example, as shown in FIG. 7D, when θ1 = 0 and θ2 = (2π / 3), ω ₁ , ω ₂ , and ω ₃ are expressed by Equation 7.

For example, as shown in FIG. 7E, when θ1 = −θ, θ2 = ((π / 2) + θ)), ω ₁ , ω ₂ , and ω ₃ have the relationship shown in Equation 8. And is shown in Equation 9.

If the angular velocity vector ω (ω ₁ , ω ₂ , ω ₃ ) is integrated, the amount of rotation of the rotor is known, and the attitude of the rotor (three-dimensional angular position) is obtained. Further, the direction of rotation of the rotor can be known from ω (ω ₁ , ω ₂ , ω ₃ ). Further, by multiplying ω (ω ₁ , ω ₂ , ω ₃ ) by the known rotor radius, the three-dimensional rotational speed of the rotor surface can be calculated. Also, by integrating the three-dimensional rotational speed of the rotor surface, the three-dimensional movement amount of the rotor surface can be calculated.

  As described above, an optical position sensor is disposed at each of two positions having a known narrow angle, and the above-described calculation is performed from the output thereof, so that the state of the three-dimensional rotation of the rotor can be determined. I can know. That is, by disposing the optical position sensor at each of the two positions having a known narrow angle, the output of the two optical position sensors disposed at the two positions is used for the three-dimensional rotation of the rotor. Rotation direction / rotation speed / rotation amount can be obtained.

(Principle verification results)
Prepare two optical position sensors with the same structure as the optical position sensor provided in the mouse used for the pointing device of the personal computer, and make the two optical position sensors have a 90 ° included angle. A jig was made to hold and hold the pseudo rotor sphere (without permanent magnet) at an appropriate distance from the sensor. Then, connect the two optical position sensors to the personal computer via the USB interface, import the spherical movement obtained from them as a numerical value from “rawinput” which is one of the APIs, and the attitude angle of the rotor ball As a result, software was created to display the current posture on the screen.

  Then, in this system, it is confirmed that the current posture is displayed as the rotor ball is rotated, and the rotational state of the rotor ball is determined using two other sensors that detect the amount of movement of the two orthogonal axes. It was verified that can be detected.

  This principle does not limit the included angle of the sensor to 90 °. Furthermore, even when three or more sensors are arranged at arbitrary positions on the spherical coordinates at an arbitrary included angle, arithmetic processing can be performed. By appropriately processing the outputs from the three or more sensors, it is possible to reduce the rotor posture detection error due to the missing amount of movement of the sensors.

(Superiority)
Since the rotation of the rotor 120 is optically detected, a rotor support mechanism such as a gimbal mechanism is not required for the purpose of detecting the rotation of the rotor 120. For this reason, the rotation of the rotor 120 is not limited due to the mechanism for detecting the rotation of the rotor 120. Further, since the optical detection is performed, the structure is simplified. Since the magnetic sensor is triggered by the passage of the magnet (change in polarity), the resolution per round is (360 ° / number of magnetic poles), while the optical sensor has a resolution of (360 ° / count) regardless of the number of poles of the magnet. ) For example, in this model, the resolution of the magnetic sensor is 90 °, but if an optical sensor with a rotor outer diameter of φ30 and a resolution of 5600 cpi (abbreviation of count per inch) is selected, the resolution becomes 0.03 ° or less when converted to an angle. Subdivision is possible compared to sensors. Since the detection output is an optical principle, the detection of the rotation of the rotor 120 is not easily affected by the complicated magnetic field configuration inside the spherical motor.

  By the way, if there is a stepped portion such as a convex portion or a concave portion on the outer peripheral surface of the rotor 120, the distance between the optical sensor and the reflecting surface varies. Further, depending on the shape of the reflecting surface, the incident light does not return to the light receiving unit, and the sensor signal (information) disappears. These cause a decrease in detection accuracy of the rotation of the rotor 120 by the optical position sensor 117 and cause of erroneous detection. On the other hand, in this embodiment, since the outer peripheral surface of the rotor 120 is covered with the cover portion 121 having a spherical surface, the above-described phenomenon that the reflected light is disturbed is suppressed, and the rotor 120 by the optical position sensor 117 is suppressed. Reduction in rotation detection accuracy and false detection can be suppressed.

  Further, the surface of the cover 121 has a smooth spherical surface, and the rotor 120 is supported by point contact from the periphery by a bearing ball of a spherical bearing (not shown), so that the rotation of the rotor 120 with three or more degrees of freedom is smooth. The state that can be performed can be realized with a simple structure.

(Other)
Three or more optical position sensors 117 may be used. In this case, an optical position sensor 117 is arranged at each of a plurality of positions inside the stator 110 at known angular positions, and the movement amount of the surface of the rotor 120 is determined by each optical position sensor 117. Count in the direction of two orthogonal axes. Based on the output from each optical position sensor 117, the rotation of the rotor 120 is detected. Specific processing at this time includes, for example, the following method. First, based on the output from each of the plurality of optical position sensors 117, information related to the rotation direction and amount of rotation of the rotor 120 is detected for each of the plurality of optical position sensors 117. Next, an abnormal value is eliminated by a statistical method, and the rotation direction and the rotation amount of the rotor 120 are acquired by recalculating the remaining detection values. By doing so, the rotation of the rotor 120 can be detected with higher accuracy.

  Information related to the rotational position of the rotor 120 calculated based on the output of the optical position sensor 117 (for example, in which direction the rotor 120 is rotated in what direction) is sent to the display device and displayed there. You may let them. In addition, information related to the rotational position of the rotor 120 calculated based on the output of the optical position sensor 117 can be sent to another device and used for controlling the device.

  The outer shell member of the rotor 120 is coated or printed so that light from the light emitting element is prevented from being transmitted or absorbed, and the light receiving element reflects enough light to detect the amount of movement, and the amount of reflected light changes due to movement. It is also possible.

  In the embodiment, an example in which a plurality of optical position sensors 117 having two outputs (two orthogonal outputs) (two in the embodiment) are used has been described, but an optical position sensor having three or more outputs is used. If there is, it is possible to configure the system using only one of them (of course, a plurality may be used). Examples of such an optical position sensor include an optical position sensor including two or more detection optical sensors.

  The aspect of the present invention is not limited to the individual embodiments described above, and may be an outer rotor shape in which the rotor is outside the stator, and includes various modifications that can be conceived by those skilled in the art. The effects of the present invention are not limited to the above-described contents. That is, various additions, modifications, and partial deletions can be made without departing from the concept and spirit of the present invention derived from the contents defined in the claims and equivalents thereof.

  The present invention can be used for a spherical motor.

  DESCRIPTION OF SYMBOLS 100 ... Spherical motor, 110 ... Stator, 111 ... Hemisphere part, 112 ... Hemisphere part, 113 ... Magnetic pole, 114 ... Bobbin, 115 ... Field coil, 116 ... Salient pole surface, 117 ... Optical position sensor, 118 ... Light emitting element DESCRIPTION OF SYMBOLS 119 ... Light receiving element, 120 ... Rotor, 121 ... Cover part, 124 ... Inner sphere part, 125 ... Rotor magnet, 131 ... Substrate, 132 ... Screw, 133 ... Screw, 134 ... Part where washer or shim is sandwiched, 200 DESCRIPTION OF SYMBOLS Optical position sensor assembly 201 ... Board | substrate 203 ... Shaft 204 ... Holding part 204a ... Cylindrical part 204b ... Flange part 205 ... Set screw 210 ... Hole 211 ... Hole 220 ... Magnetic pole assembly

Claims (9)

A mechanism for detecting the operation of a rotor of a spherical motor rotatable in an arbitrary direction by an optical position sensor having an output number of 3 or more;
The mechanism includes a rotor rotation state calculation unit that calculates a rotation state of the rotor,
The optical position sensor detects a velocity component in three directions on the rotor surface,
The rotor rotation state calculation unit calculates a three-dimensional angular velocity vector ω = (ω ₁ , ω ₂ , ω ₃ ) based on the three-direction velocity components on the rotor surface . The optical position sensor is disposed at at least two positions of an angle forming a known included angle,
The positions of the optical position sensors arranged at the two positions are indicated by vectors r ₁ and r ₂ with the rotation center as the origin ,
The vector _{r 1} and the three-dimensional angular velocity vector omega = based on velocity component and the components of the vector _{r 1} and _{r 2} in a specific direction at the position of _{r 2 (ω 1, ω 2} , ω 3) that is calculated The spherical motor according to claim 1. By integrating the three-dimensional angular velocity vector ω = (ω ₁ , ω ₂ , ω ₃ ), the rotation amount of the rotor is calculated,
3. The rotational speed of the rotor surface is calculated by multiplying the three-dimensional angular velocity vector ω = (ω ₁ , ω ₂ , ω ₃ ) by the radius of the rotor . Spherical motor. The rotor has a spherical surface covered with an outer shell member,
Coating or printing in which the outer shell member of the rotor prevents light from being transmitted or absorbed from the light emitting element, reflects light necessary and sufficient for the light receiving element to detect the amount of movement, and the amount of reflected light changes due to movement. The spherical motor according to any one of claims 1 to 3, wherein the spherical motor is provided.   5. The spherical motor according to claim 1, further comprising an arithmetic mechanism that performs arithmetic processing on a signal detected from the optical position sensor to calculate a rotational state of the rotor. 6.   The spherical motor according to any one of claims 1 to 5, wherein a distance from the optical position sensor to the rotor is 1.0 to 3.0 mm.   The spherical motor according to any one of claims 1 to 6, wherein a diameter of the rotor is 40 mm or less.   The spherical motor according to any one of claims 1 to 7, further comprising a distance adjusting unit capable of adjusting a distance between the optical position sensor and the outer peripheral surface of the rotor. A substrate on which the optical position sensor is mounted;
A shaft for holding the substrate;
A shaft holding member that holds the shaft in a state in which the shaft is movable in the axial direction,
The shaft holding member is fixed to the stator of the spherical motor;
The spherical motor according to any one of claims 1 to 8, wherein the distance between the optical position sensor and the outer peripheral surface of the rotor is adjusted by moving the shaft.

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